Heat exchanger



NOM 26, 1940. 1 A GIBB 2,223,318

HEAT EXCHANGER Filed sept. 14, 1959 j@ j /////////III 'J4 lNvENToR Patented Nov. 26, 1940 HEAT EXCHANGER.

John A. Gibb, New Rochelle, N. Y., assignmto The Lummus Company, New York, N. Y., accr-v poration of Delaware Applicata@ september ii, 1939, serial No. 2943er 4 Claims.

preferably made suiciently small in diameter soY the tube bundle can be withdrawn from the shell. My present invention relates to the manner by I' l5 which` thecover is secured to the tube sheet so that the cover and the securing means can be removed from the tube sheet in such a manner that the tube sheet can be withdrawn through the shell. 20 The principal object of the present invention is to provide a simplied securing means by which a cover can be secured to the floating tube sheet of a heat exchanger with adequate provision against loss of sealing pressure, irrespective of 26 variations in expansion and contraction of the parts in service.

Another and more specic object of the invention is toprovide a oatlng head cover assembly having a minimum number oi parts and a 80 lminimum amount of machining required to produce the assembly, and so that theconstruction is relatively inexpensive and will withstand the duty required. t

A still more specific object of the invention is 35 to provide a floating tube sheet and cover assembly in which the correr is `secured by a continuous ring or annular member, which, in turn, is detachably keyed to the tube sheet by a plurality of flat, partially circular key members.

'40 Further objects and advantages of the invention will appear from the following description of a preferredform of embodiment thereof, taken in connection with the attached drawing, in which, '45 Fig. 1 is a substantially central vertical section through a part of a shell and tube type heat exchanger;

Fig. 2 is a partial horizontal section with parts broken away, taken substantially along the line 50 2-2 in Fig. 1;

Fig. 3 is avdetailed vertical section through a vmodified form of securing device; Fig. 4 is aview similar to Fig. 3 and showing a still further modied form of construction. 55 In accordance with the preferred form of embodiment of my invention, the heat exchanger shell lll, which is sealed at'one end, by the cover I2, is provided with a tube bank AI4 withone end of the tubes fixedly secured to shell l in any well-known manner, as by'a fixed tube sheet (not shown). The other end of the tube bank I4 is provided with oating tube sheet I6 so that the tube bank may expand and contract in a suitable manner. 'Ihe oating tube sheet I6 is normally of slightly smaller diameter than the interior of 10 the shell I0 so that the tube bundle I4 may be removed. A

As is also Well-known, the floating tube sheet I6 is necessarily provided with a tube sheet cover I8 which acts as a channel for the transfer of 15 uidsfrom one part of the `tube bank to the other. In accordance with vmy invention, the iioating tube sheet cover I B'has a rim i9 to engage the gasket which directlyrests on the margin of the floating tube sheet I6. Preferably, 20 the floating tube sheet cover I8 is of the same diameter as the floating tube sheet I6.

The securing means to hold the cover to the tube sheet, which is the substance of my inven-I tion, includes a continuous annular ring 22 which 25 is provided with a depending portion 24 which surrounds the rim I9 on the floating tube sheet cover I8 and also surrounds therfloating tube sheet I6. The lower portion of this depending portion 24 is conveniently anchored to the float- 30' ing tube sheet I6 as by a pluralityoi key-like members 26. These key-like members are similar to the well-known Woodrui keys in that they are relatively ilat members, partially circular, and may be projected through the wall of the depending portion 24 into the tube sheet I6. y

As shown in Fig. 2, the tube-sheet I6 may be conveniently provided with a continuous groove 28 to receive the keys 26, it being understood that the keys are placed in shear along the dotted line portion 29. The extent of the shear section can,v oir course, be varied to suit the desired operating conditions. i

'I'he openings for thekeys 26 are conveniently made by automatic machinery, and close fits can 5 be obtained. Furthermore, there is`no. tendency of the keys to move outward and a ve`ry secure connection can be made. With the continuous groove 28, there is no need to index the depending portion 24 with the tube Sheet, although, of 50 course, if indexing were desirable, it Awould be relatively easy to form the key slots in the depending portion'Zl, and in the tube vsheet i6 simultaneously.

The annular member 22 is also provided with 65 an overhanging ilange portion 30 to receive adjustable screw members 32, which co-act with the boss portion 34 on the oating tube sheet cover I8. From inspection of Fig. 1, it will be apparent that the tube sheet cover I8 is held tight against removal by the bolts 32 with a direct reaction on the tube sheet I6. Removal of the cover I8 is accomplished when shell cover I2 is removed y by merely loosening the bolts y32. The keys 26 can then be quickly' removed by tapping on one edge and thereafter the annular member 22 and the cover member I8 can be removed.

'I'he construction described is very economical, as it merely requires that the tube sheet and cover be turned to a common diameter with the tube sheet suitably grooved intermediate its top and bottom edges. 'I'he annular member 22 is also-a relatively simple element, which is slotted at spaced intervals to receive the desired number of keys. The apparatus can be assembled and disassembled by unskilled labor and can be made extremely tightl and will withhold high pressures, irrespective of diameter changes, it being noted that the screws 32 are in compression, with the result that there is no material change in expansion between the inner and outer portions consisting, respectively, of the depending part 24 of the annular ring 22 and the boss portion 34 of the cover I8.

The modified form of construction shown in Fig. 3, in which the floating tube sheet is indicated at 4I), is adapted to have the same type of tubes forming the tube bank I4, and is provided with a similar type of cover I8 which is secured thereto by the annular member 22 through the adjustable bolts 32.' The keys 26 are also of the type shown in Fig. 2, but in this construction the keys 26 enter into a hardened ring member 42, which is recessed into the tube sheet 40.

Under some circumstances, the tube sheet 40 may be of such a material, such as bronze, that the unit stresses are so great that the keys 26 would cause a deection within the tube sheet.

In such case, the Vuse of a hardened supplemen` tary ring member, such as 42, which can be recessed within the tube sheet, offers an eiective connection.

A further alternative construction is shown in Fig. 4, in which the cover I8 is secured to the tube sheet I6 by an annular ring 45 and held by the adjustable bolts 32 in a manner similar to the construction shown in Fig. l. In this case, however, the depending portion 46 of the annular member is somewhat greater in extent than the same construction as shown in Fig. l, and the keys 26, which are projected through the wall thereof, extend below the bottom of the tube sheet I6. This is particularly advantageous in case of very thin tube sheets where it may be aazasis found undesirable to form the groove 28 as shown in Fig. 1.

While I have shown preferred f orms of embodiment of my invention, I am aware that modiiications may be made' therein and I, therefore, desire a broad interpretation of my invention within the scope and spirit of the disclosures herein and of the claims appended hereinafter.

I claim:

1. In a heat exchanger of the class described having a shell, a tube bundle therein, including a tube sheet xed to the shell, and a floating tube sheet removable through said shell, the combination of a cover for said tube sheet and means to secure said cover to said Itube sheet, said means comprising a continuous ring member surrounding the periphery of the cover and tube sheet, multiple anchoring means engaging both the continuous ring member and the tube sheet to anchor the ring member against movement with respect to the tube sheet, and adjustable members engaging the cover and reacting through the ring member whereby on adjustment the cover may be forced against the tube sheet, said anchoring means being a series of projecting keys having a semi-circular contour and projecting through the' wall of the continuous ring member so as to be rotatable from the exteriorthe space between the keys being approximately equal to the width of the keys.

2. In a heat exchanger of the class described having a shell, a tube bundle therein including a tube sheet fixed to the shell and a floating tubey sheet removable through said shell, the combination of a cover for said tube sheet and means to secure said coverto said tube sheet, said means comprising a continuous ring member of inverted L-shape in cross section, one flange of whichoverlies the cover, adjustable members carried by said ange and adapted to engage the cover, the other portion of said continuous ring member being substantially cylindrical and overlying the peripheries of the cover and the tube sheet, and a plurality of key members projecting through the wall of said continuous ring member and projecting beyond the outer diameter of said tube sheet, said projecting keys being retained in operative position by a part of the heat exchanger shell.

3. In a heat exchanger of the class described in claim 2, the projecting keys being iiat and constituting an anchoring surface of substantial extent, against which said tube sheet reacts.

4. In a heat exchanger of the class described in claim 2, the tube sheet being recessed on the surface opposite that which the cover engages and being provided with a supplemental ring, such supplemental ring being recessed to receive the projecting keys.

J OHN A. GIBB. 

